Barking machine having feed roller power-driven at certain peripheral speed or log-driven at higher speed



Dec. 18, 1956 N. e. LEFFLER 2,774,397

BARKING MACHINE HAVING FEED ROLLER POWER-DRIVEN AT CERTAIN PERIPHERALSPEED OR LOG-DRIVEN AT HIGHER SPEED Original Filed Oct. 31, 1952 '2Sheets-Sheet 1 M Hillllll L"; lllmlllll INVENTOR.

Pm, W 9 PM Dec. 18, 1956 G. LEFF'LER BARKING MACHINE HAVING FEED ROLLERPOWER-DRIVEN AT 2,774,397 CERTAIN PERIPHERAL SPEED OR LOG-DRIVEN ATHIGHER SPEED Original Filed Oct. 31, 1952 2 Sheets-Sheet 2 7 8 IO 26 p ir INVENTOR. M

United States Patent POWER-DRIVEN AT CERTAIN PERIPHERAL SPEED ORLOG-DRIVEN AT HIGHER SPEED v.) Nils Gustav Leflier, Sundsbruk (nearSundsvall), Sweden,

assignor to Svenska Cellulose Aktiebolaget, Stockholm, Sweden Originalapplication October 31, 1952, Serial No. 317,980. Divided and thisapplication February 12, 1954, Serial No. 409,912

Claims priority, application Sweden November 3, 1951 Claims. (Cl.144-247) This invention relates to improvements in barking machines ofthe kind having at least one barking member movable into and out ofengagement with the log, said machines having at least one of the twoelements, the barking member and the log, adapted to rotate relativelyto the other. The invention consists mainly therein, that in the feedingpath of the log there is rotatably provided at least one memberconnected to a driving mechanism and resting against the log being fed,said rotatable member being so arranged in supporting means swingableunder the influence of the log, that its journal axis and the axis ofthe swinging shaft of the supporting means are situated on oppositesides of the axis of the log, the axis of said swinging shaft beingspaced from the periphery of the log, and the rotatable member restingagainst the log with a pressure which not only depends on the feedingresistance but which will increase automatically with increasing feedingresistance.

An exemplary embodiment is shown in the accompanying drawings. Fig. l isa side elevation of the machine, a portion of the outer casing beingbroken away, and other parts being broken away and shown in section tobetter reveal the mechanism within it. Fig. 2 is a composite sectionalview of the right hand end of the apparatus as shown in Fig. l, asindicated by the section lines 2L-2L and 2R2R. Fig. 3 is a detailelevation ofthe roller conveyor at the right hand end of the apparatusshown in Fig. 1, as indicated by the line 3-3.

Referring to the drawings, 1 is a rotary drum or the like (Fig. 1),which by means of bearings 2 is supported by a nonrotary tube 3 rigidlysecured to a frame 4. In the drum 1 one or more, for example six, shafts5 are turnably mounted. At one end of each shaft 5 there is secured abarking member 6 in the shape of a scraping element located within anannular stationary bark-collecting housing 44. Inside a bearing plate 7there is secured to each shaft 5 a sleeve plate 8 actuated by one end ofa helical spring 9, which at its other end is secured to a sleeve plate10, which is adapted to turn on the shaft 5 and to which a centrifugalweight 11 is secured. In Figures 1 and 3 the log 12 is shown. Fordamping the movement of the weights 11 and, consequently, also of thebarking members 6 rubber plates 13 are provided.

Upon rotation of the drum 1 the centrifugal Weights 11 are thrownoutwards, each weightactuating by way of the sleeve'plate the" spring'Qan'dth'en also the barking member 6, which thus-is pressed inwards readyfor engagement with the log.

For feeding the logs the following means are provided. 7

As will be seen from Figures 1 and 2, feed rollers 19 are mounted onarms 20, the latter being turnably mounted on brackets 21. 'In orderthat the log shall always be kept at the reenter the. arms'20 areconnected to an arm 23 by means of links 22, said arm being in turnmounted in a bracket 24 secured to the frame. The driving of the rollersmay be provided for by a cylindrical gear 25 and a chain drive 26. Theshaft of the gear 25 may be absorber 29.

driven from a power source (not shown) which is connected to the shaftby means of a key-groove 48. The drive between the two feedingmechanisms formed by the rollers 19 may be transmitted by means of achain or, for example, by means of a horizontal shaft, two chain wheelsbeing required in the former case and two mitre gears being required inthe latter case. Said details are not shown in the drawings. The driveof the upper rol-' ler is effected by means of a chain 27. The contactpressure is obtained from a spring 28 and the bump arising when the logis leaving the rollers is damped by a shock The conveyor may be made asa belt conveyor, as sh'ov or as a roller conveyor in avconventionalmanner and cooperating shoulders 47.

preferably it is driven at the same peripheral speed as" that of thefeeding mechanisms. The roller 31 is, however, arranged in a'specialway, bringing about considerable advantages.

As shown in the drawings the roller 31 is turnably mounted by a shaft 43bearing in the free ends of two arms 32. Said arms 32 are attached attheir lower ends (e. g. welded) to a sleeve 45 which is journalled on ashaft 33 between two brackets 34. The ends of the shaft 33 are turnablymounted by the brackets 34. The contact pressure of the roller isadjusted by means of springs 35 and the degree of compression of thesprings should be so chosen that the roller will contact the log with aslight pressure. p

The roller 31 may be driven by means of a separate motor or also, asshown in the drawing, from the fore feeding mechanism. A chain wheel 36is provided'on the gear 25 and drives the shaft 33 by way of a chainwheel 37, which may be connected to an overrunning clutch 33 The clutchillustrated has spring operated pawls 46 and On said shaft 33 there issecured a chainwheel 39, which by way of a chain 40 and a chain wheel 41drives the roller 31. The gear ratios may be chosen in such a mannerthat the roller 31 is driven at a somewhat lower but certain peripheralspeed than are the rollers of the feeding mechanisms, and'theoverrunning member of the clutch should be arranged in V such a mannerthat it wiil be in engagement when, by means of the chain driving means,the roller is driven at the abovementioned certain peripheral speed, butit should admit of the roller being driven at a higher peripheral speedby the log. It is not necessary in this connection to deal moreparticularly with the construction of the overrunning clutch, becausethe abovemen tioned condition will be obtained by any conventionalone-way engaging clutch which automatically transmits torque in onedirection of movement but not in the opposite direction.

If the driving of the roller 31 is arranged in this way, said rollerwill serve as an auxiliary roller, i. e. it will not feed the log exceptin case the speed or" the latter should become reduced for some reasonor other, so that its speed will become-lowerthan the certain peripheralspeed; of the roller. Consequently, the feeding means" of machine willfunction in the following mannerrBy means of a device not shown in thedrawing a logis placed on the conveyor 30 and by the latter is movedtoward the barking members. The log will first meet the roller 31, andwill then simultaneously swing it upward and toward the drum, so thatthe log is able to pass under the roller.

Since the roller is partly balanced by the spring 35 the Patented Dec.18, 1956 come too large."

a s t t o with a log. The contact pressure of the roller against the 7log will of course also be very low and feeding spikes 42 'of the rollerwill make no marks or markings in the Wood' that will cause theformation of splinters in the surface of the log, when the barkingmembers are applied.

Next, the log meets the fore rollers 19 of 'the feeding mechanisms. Ifthe log enters directly betweenthe same then no change takes place inthe mode of Operation of the roller 31. Should the log, however, bestopped by the rollers 19, the roller 31 will take over the feeding andwillcause thelog to enter between the rollers 19. The axial or feedingcomponent of;tlie contact pressure of .the roller 31 on the log will'then be dependent on the 7 existing feeding resistance, and it isadvantageous that the greater the'feeding resistance, the g'reatehwillbecome the feeding component of thecontactpressure. Itis very easy topredetermine therelation between the horizontal feeding component andthevertical component by choosinga proper initial angle of inclinationfor the arms'32,

It is advantageougtoo, for the contact pressure to increase i log, meansconnecting said member to a driving mechlog, said supporting means beingswingable about a second having at least one barking tool movable intoand out of engagement with an axially fed log, the barking tool and thelog being relatively rotatable about a longitudinal axis. of an axiallyfed log; and: said machine having conventional means for feeding a logat a given axial spee d, said improvement comprising at ,leastoneyrotatably driven member located in a feeding. path'of an'axially fedanism which rotates said member at a certain-peripheral speed notexceeding said given axial speed of a'log, means 7 supporting saidmember for rotation about an axis transverse to and spaced from saidlongitudinal faxis of '2. fed

transverse axis spaced froni that; side of saidilongitudina'l axisopposite to said first transverse axis and also} spaced from saidlog-feedingpath an oncoming :log' 'e n gaging' V said member andswinging said supporting means about 'When debarking thick logs, andthis occurs because the 7 arms 32 will bemoved to a more verticalposition than by thin logs and will correspondingly, increase thecompres? sion of the spring 35.

As soon as the log has entered between the fore rollers 19 it will bedriven by said rollersat the higher peripheral speed. The feedingcomponent of the contact pressure of the roller. 31 on the log will thenbe reduced to zero orless, as before the introduction of the logbetweenthe rollers 19, and the roller 31 will again be rotated by the 'log. p 7When the log then meets the barking members 6, the 7 samecondition'sarise as'when itmetthe fore rollers 19. It said rollerstareable to'pres s the log in between the ibarking members the roller 31will not carry outany feeding work but it will begin to drive the log,if the log should said second transverse axis until said memberrestsagainst V a log, whereby said driving mechanism willflcause'saidmember to drive a log forward only when the axial speed: a of a log,becauseof too much feeding resistance, drops' 1 below said certainperipheral speed. 7

2. An improvement in a barking machine of the; kind having at least onebarking tool movable into and out of engagement with an axially fedlog,the barkingtool and'I the log being relatively rotatable about alongitudinal axis of an axially'fed' log, and said machine having con-iV ventional means for feeding a log ata. given axial speed,

slowdown or stop. There is no risk of the feeding pressureof the roller31 becoming so high that parts of the machine would be pressed asunder,becausethe feeding spikes 42 ofithe roller are not made sollargethatthey will penetrate the wood, incase the resistance should be- I The.roller 31 brings and the back rollers 19 apart; Such damaged'areas of'the woodwould subsequently be increased by the scrap-.

ing action of the barking members. Furthermore, the

log will skid sometimes on the .conveyor'30 and'will not enter betweenthe fore rollers 19. By the provision of low, namely, only such pressureas is required for the barking operation alone. Should the log be sloweddown orstopped the roller 31 begins to drive the log in the mannerpreviously mentioned. Thedamage to'the wood which may be caused by saidroller can be overlooked because this will only take place along veryshort parts i of the length of the log. V a V V Ofcourse itis notnecessarythat the 'roller 31 be driven tudinal axis" opposite to'saidfirsttransverse axis and also' spaced from said log-feeding path,ranoncor'ninglog en-g gaging said memberand swinging said s pporting meansabout said. second transverse axis untils'aidmernber rests j aboutconsiderable advantages. Q Thus the surface'of the wood may easilybecome damaged; a by the fore rollers'19 Whenever they have tobefpressed against the log hard enough to cause a high feeding pres-. Vsure, as when the log has to'press the barking members said improvementcomprising'at least one rotatably'driven member located in a' feedingpath of'a'n axially fed-log,

means connecting saidmember to afdriving mechanism whichrotates'said'meniber at a certain peripheral speed which is lessthan'saidgiven axial speediofa log, meansiqi supporting said member forrotation about an axis transverse to and spaced from said longitudinalaxis of a fed 'log, saidsupporting means being swingable about'a, sec

ondtransverse axis spaced from that side of saidv longiagainst a log,whereby said membe'r is driven by alogat a peripheral speedwhich'ishigher than said certain pie-l; riph'eral, speedjwhenever a logdoes not: encounter too much feeding'resis tance, and whereby. saiddriving mocha anismvvill cause said member-to drive a log forwardonlywhen the'axial speed of a l'og, because :of too muclifeeding j-resistance,vdrops, belowsaid certain peripheral speed.

3, An improvement.according to claim 2, said machine including a springfor pressing 'said member against a 7 log, the biasing force of saidspring being greater for thick the roller 31 the contact pressure of therollers 19 can be. I

by means of; an overrunning clutch;- lt'may be driven directly by achain driveand attheisame peripheral speed that will be. dependent onthe feeding resistance.

'No. 317,980 filed Oct. 31, 1952. V V Having' now described myinvention, wha'f'I clainr as 7 new and desire to secure by LettersPatent is: t

1 .An improvementinaibarking machine. of the kind thgconvyorBG and oftheifeed rollers 19. It a will'then gbe feeding'alhthe time with acontactpressure Q i This application is a division of .my applicationSerial f logs than for. thin logs.

speedih j V p V, Refe ren cescitedin thefileotthis paientgi W t, i 1TEDSTATES PArENTsrf; j;

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